A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.
The present invention is related to computer software and more specifically to management software for computer networking equipment.
Moving information between two points may involve several computer networks. To send data to a remote site, the data may be sent to a router coupled to the sender""s network, sent over a network service provider""s network, and received by a router at the recipient""s network.
In many cases, the network service provider is a company distinct from the sender or the recipient, such as a telephone company, that provides communication and switching services to the sender and recipient. The routers at the sender and recipient communicate with switches operated by or for the network service provider.
If the network service provider""s network is an ATM network or frame relay network, information may be moved through the use of virtual circuits. A virtual circuit defines a path between two points of a network, and a physical data link may be used to carry the information from multiple virtual circuits.
The user of a network service provider pays for service meeting certain parameters which define a Quality of Service for the virtual circuit between the sender""s router and the network service provider""s switch. If the network operated by the network service provider is a frame relay network, these parameters may include one or more of a committed information rate (CIR), committed burst size (Bc), excess burst size (Be), maximum frame size, or priority. The network service provider configures its network to provide service to the user that meets these parameters. One way of configuring the network is by communicating these parameters to one or more of the switches that make up the network service provider""s network. Software in the switch attempts to ensure that sufficient capacity exists to meet the requirements defined by the parameters, and attempts to supply up to this capacity as the data received by the router requires.
If the sender supplies data via a virtual circuit to the network service provider""s network that exceeds the Quality of Service for such link for which the user has paid, the response by the network may be uncertain. Therefore, for each virtual circuit the user maintains to the network service provider""s switch, the sender will attempt to keep the level of data it sends within the Quality of Service for which it has contracted. Because the sender""s router supplies data to the network service provider""s network, the sender will configure its routers to prevent them from exceeding the Quality of Service provided by the network virtual circuits.
To configure the switches of the network service provider, the network service provider supplies the Quality of Service parameters to one or more of its switches. To configure the router, the sender must supply the Quality of Service parameters to its routers.
Supplying Quality of Service parameters to routers can be a time-consuming and error-prone task. Each router requires certain Quality of Service parameters for each connection in the network. If a Quality of Service parameter for a virtual circuit does not match that of the switch with which the router communicates, either the router will overload the switch with uncertain results, or the router will underutilize the switch, wasting capability for which the user is paying. If the parameters are changed in the switch, the parameters in the router must also be updated to match, resulting in another time-consuming and error-prone task that can cause the same problems described above if not performed properly.
What is desired are a method and apparatus that ensures the Quality of Service parameters in the switch match the Quality of Service parameters in the router and reduces the effort involved in communicating such parameters. Because of the large installed base of switches and routers, it is desirable that the method and apparatus implemented on a switch operate with routers that do not utilize such method or apparatus, and the method and apparatus implemented on a router operate with switches that do not utilize such method or apparatus.
A method and apparatus allows Quality of Service parameters to be received by a router or other user equipment devices from a switch or other network equipment device, thereby eliminating the duplicate entry of such parameters to the router and ensuring the parameters in the router match those of the switch. When a new connection is established between the switch and the router, the switch can request the router to send either a list of available protocols or an indication of whether it can support the features of the present invention. If the router detects a protocol that provides the other features of the present invention, the router instructs the switch, either implicitly or explicitly, to communicate using that protocol. The router can then request the switch to send the Quality of Service parameters it has for various virtual circuits. The router can then use the parameters received from the switch for conventional routing operations. In the event that the switch changes its parameters or adds parameters for a new physical or logical connection, the switch informs the router of the change. The router can then request the switch to resend its parameters. The method and apparatus allows the parameters in the router to match the parameters in the switch while reducing the effort to maintain these parameters in the router in a manner that allows equipment to be compatible with other equipment that does not implement the method and apparatus described herein.